The present application relates to an electronic device, a method of manufacturing the same, and a storage device that make use of a phenomenon in which, for example, when voltage is applied to an air gap formed by two conductors, a change occurs in the resistance between the conductors.
As an electronic device that is electrically rewritable and maintains a memory state even if a power supply is turned off, there is a flash memory (or a flash ROM). The flash memory is an electronic device that has a storage cell including one floating-gate transistor and is characterized by low bit cost. The flash memory is considered to be further advanced in scaling for the storage cell in order to realize bit cost advantageous for memories of other specifications.
However, such a flash memory may cause a phenomenon in which charges accumulated in a floating gate electrode are erased by a leak current of a tunnel oxide film generated according to an increase in the number of times of rewriting of data. This phenomenon rapidly increases according to thin-filming of an oxide film. Therefore, the scaling of the storage cell is not easy and scaling not depending on the thin-filming needs to be performed.
From the viewpoint explained above, researches and developments of nano-structure represented by functional organic molecules and ultra-micro particles have been actively carried out. The researches and developments are applied to refining of electronic devices. As an application of the nano-structure, there is an electronic device in which, for example, two electrodes are arranged across a micro air gap (gap; hereinafter referred to as gap) and the gap is bridged by functional organic molecules.
In ‘A [2] Catenane-Based Solid State Electronically Reconfigurable Switch’, Charles P. Collier, et al., Science, Vol. 289, pp. 1172-1175 (2000) (Non-Patent Document 1), an electronic device in which a catenane-based molecules are arranged in a gap of electrodes formed of platinum is disclosed. According to Non-Patent Document 1, when voltage is applied between the electrodes, the catenane-based molecules are subjected to the oxidation-reduction reaction and perform a switching action.
As other applications of the nano-structure to electronic devices, there are disclosed a method of manufacturing a nanogap electrode having a gap space of about several nanometers (see, for example, JP-A-2005-79335 (Patent Document 1) and JP-A-2006-234799 (Patent Document 2) and an electronic device in which voltage is applied to a gap between metals to which only a tunnel current flows and a hysteresis effect appearing in resistance is applied to a switching action (see, for example, ‘Resistance switch employing a simple metal nanogap junction’, Yasuhisa Naitoh, et al., Nanotechnology, Vol. 17, pp. 5669-5674 (2006) (Non-Patent Document 2) and JP-A-2007-123828 (Patent Document 3)).